[FFmpeg-cvslog] avcodec/fitsdec: Fail on 0 naxisn

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Sep 30 08:50:41 2019 +0200| [4a3303d52096337dc109fbd523ecb4b46cddace1] | committer: Michael Niedermayer

avcodec/fitsdec: Fail on 0 naxisn

Fixes: Timeout (100+ sec -> 23ms)
Fixes: 17769/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FITS_fuzzer-5678314672357376

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4a3303d52096337dc109fbd523ecb4b46cddace1
---

 libavcodec/fitsdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/fitsdec.c b/libavcodec/fitsdec.c
index a20b8faf9e..1f06754f8b 100644
--- a/libavcodec/fitsdec.c
+++ b/libavcodec/fitsdec.c
@@ -143,7 +143,7 @@ static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSHead
 
     size = abs(header->bitpix) >> 3;
     for (i = 0; i < header->naxis; i++) {
-        if (size && header->naxisn[i] > SIZE_MAX / size) {
+        if (size == 0 || header->naxisn[i] > SIZE_MAX / size) {
             av_log(avctx, AV_LOG_ERROR, "unsupported size of FITS image");
             return AVERROR_INVALIDDATA;
         }